Hair straightener



FIG. 1 is a front perspective view of a hair straightener showing our new design in an open position;

FIG. 2 is a rear perspective view thereof showing the hair straightener in a closed position;

FIG. 3 is a side view thereof showing the hair straightener in the open position;

FIG. 4 is a side view of the opposite side of FIG. 3 showing the hair straightener in the closed position;

FIG. 5 is a top view thereof;

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a front view thereof showing the hair straightener in the closed position.

The broken lines shown in the drawings illustrate portions of a hair straightener that form no part of the claimed design. 

CLAIM We claim the ornamental design for a hair straightener, as shown and described. 